1. Field of the Invention
The present invention relates to adapters to connect a video camera to a microscope and more particularly to such an adapter for connecting a surgical or diagnostic microscope to a camera.
2. Related Art
At the present time a number of adapters are commercially available to connect a "video" camera to a microscope. Video cameras includes video analog, digital video and digital still cameras, including single and multiple CCD (Charge Coupled Devices). Generally the video camera is small and uses a solid-state electronic imaging device, such as a CCD (Charge Coupled Device). The microscope may be a stereo bright field microscope. Such adapters are available from leading scientific and surgical/diagnostic microscope manufacturers including Nikon, Leica-Wild and Zeiss.
When surgical stereomicroscopes are used for certain types of surgery or diagnoses, such as surgery on the ear, nose, throat, brain, spinal cord and eye (especially retina surgery) and other types of microsurgery or diagnoses, it is important that the exact location of interest be centered in the field of view of the image plane of the video camera and that the image be in focus. The image is displayed on a monitor and may be viewed by the operating surgeon, other members of the surgical team and students. The image may be broadcast, for example, a real-time image may be broadcast on the Internet.
In eye surgery, although the patient is fully anesthetized, the eyeball is dynamic and may move. When it does, its image on the monitor also moves so that the operative site may not be centered, and may not even be on the monitor's screen. In brain surgery often the site of the operation is at the edge of the opening, so that it may become outside of the field of view of the camera. In ear surgery the microscope is often tilted at different angles during the operation, which may cause the operative field to be out of the center or field of view of the camera.
In some industrial applications, such as the microscope inspection of circuit boards and integrated circuits, the device being inspected may move slightly during the inspection. It would be useful to move the image, without moving the microscope, the device being inspected or the camera.
If the point of surgical interest is a portion of a patient's retina and it is off-center or out of focus, or even so far off-center to be off the monitor's screen, the displayed image may be confusing or misleading. In many critical surgical operations it is important that the image on the monitor screen is on-center and in-focus. It would be desirable if the image could be moved by an operator, independently from the movement of the microscope and without interfering with the surgeon's delicate work.
Generally the surgeon is fully occupied by the operation and would not move the microscope or the camera to center the image. Also generally the surgeon would not want the microscope touched in order to center the image, as it might disturb his view through the microscope.
U.S. Pat. No. 5,052,789 shows a television camera connected to a stereoscopic microscope. The optical path to the camera includes a pair of prisms and focusing lenses. However, there is no disclosure of a centering mechanism or how the focusing lenses are controlled. U.S. Pat. No. 5,497,267 is entitled "Video Microscope" and was cited in the parent U.S. Pat. No. 5,652,676, incorporated by reference herein.
U.S. Pat. No. 5,002,376 at FIG. 2 shows a surgical stereomicroscope having a zoom tube for a camera. U.S. Pat. No. 4,277,130 discloses a zoom lens system for a camera in a stereomicroscope.